Washing machine cylinder balancing apparatus



Dec. 19, 1950 KAHN ETAL 2,534,268

WASHING MACHINE CYLINDER BALANCING APPARATUS Filed May 31, 1946 5Sheets-Sheet l SUPPLY POWER SELECTOR DISTRIBUTOR AMPLIFIER DISTRIBUTOR jIn 30:90

ATTORNEY Dec. 19, 1950 L. M. KAHN :rm. 2,534,268

WASHING MACHINE CYLINDER BALANCING APPARATUS Filed May 31, 1946 5Sheets-Sheet 2 Dec. 19, 1950 Filed May 31, 1946 L. M. KAHN ETAL WASHINGMACHINE CYLINDER BALANCING APPARATUS 5 SheetsSheet 3 T0 ViBRATlON PICKUPCYCLE FT F7 I x7 I J7 1T5 L FIRING i l I VO/LTAGE 1 FLE -"LEL /5bgmwmpw;

l r I Dec. 19, 1950 L. M. KAHN rm 2,534,268

WASHING MACHINE CYLINDER BALANCING APPARATUS Filed Bay :51, 1946 5Sheets-Sheet 4 PF 'Fl I FIIRING I a o K 0 h ll By fduna c %%-Ev Dec. 19,1950 M. KAHN ETAL wmmc ncamz CYLINDER BALANCING APPARATUS Filed lay 31,1946 5 Sheets-Sheet 5 Firs--11.-

Patented Dec. 19, 1950 WASHING MACHINE CYLINDER. BALANCING APPARATUS LeoM. Kahn and Edwin Ellner, New York, N. Y.; said Ellner assignor to saidKahn Application May 31, 1946, Serial No. 673,680

24 Claims.

. 1 This invention relates to damp drying systems for laundry machineswherein the extraction of washing fluid from the washed articles iseffected through high speed rotation of a perforated cylinder.

As was described in the prior and sole application of Leo M. KahnSerialNo. 620,038, filed October 3, 1945, wherein many of the structuraldetails of the instant washing machine were disclosed, the drying ofarticles in machines of this. type depends upon the generation of thecentrifugal force accomplished by high speed rotation of the cylinder soasto eject the wash water through its perforations. However, thegenerally unsymmetrical distribution of the articles, particularly in ahorizontal axis cylinder, often produces severe vibration which imposesa limit upon the speed of rotation and affects thereby the degree andtime of drying. The above application Serial No. 620,038 was directed tothe provision of peripherally disposed pockets to which was applied acounterbalance weight in the form of water so as to neutralize theeffect of improper weight distribution within the cylinder. In addition,the means chosen to supply the counterbalancing water to the properpockets involved an empirical process wherein the effects of adding thewater arbitrarily were measured in terms of increased or reducedvibration of the rotating cylinder. The instant application, however,has

' as its principal object the effective identification of a particularportion of the cylinder in which the overweight occurs and the automaticapplication of weight counterbalance material to neutralize suchoverweight and secure a satisfactory rotating balance.

Another object of this invention is to select and momentarily isolatespaced peripheral portions of the rotating cylinder and simultaneouslytest such portions for unbalance. Such selection and isolation isproduced by means synchronized with the rotation of the cylinder. Alliedwith this ob- Ject is the provision of means to continue the applicationof counterbalancing forces to the correct portions of the rotatingcylinder notwithstanding continued rotation whereby other portions ofthe cylinder are presented for unbalance testing. However, whenthecorrect portion has already been established, the continued rotationdoes not have the effect of either momentarily discontinuing suchapplication or shifting it to other and incorrect portions of thecylinder.

Another object of this invention is to provide a series of spacedperipheral pockets on a washing machine cylinder combinedwlth means toapply a counterbalance to more than one of the pockets simultaneouslyaccording to the site of unbalance in the cylinder. Thus, where theunbalance can not be corrected by injecting material in only one of thepockets, it may be secured by so treating a plurality of the pockets.

Still another object of this invention is to produce a balancing systemfor rotating washing machine cylinders which is simple, economical tomanufacture and requires a minimum of operating parts.

Other objects of our invention will be apparent from the followingdescription, it being understood that the above general statements ofthe objects of our invention are intended to describe and not limit itin any manner.

Referring to the drawings:

Fig. 1 is a side view in elevation, partly in section, of a preferredembodiment of the instant invention.

Fig. 2 is an enlarged, fragmentary, cross sectional view of the valvedweight injecting end of the machine.

Fig. 3 is a cross sectional view taken along the line 33 of Fig. 2.

Fig. 4 is a schematic circuit diagram of the electrical controls forapplying the counterbalance forces.

Fig. 5 is a schematic representation of the cylinder and illustrating aparticular portion thereof having an excess of weight which requiresneutralization.

Fig. 6 is an electrical diagram illustrating the action of theelectronic tubes in response to the condition of unbalance representedby Fig. 5.

Fig. 7 is an electrical diagram illustrating the action of the tubes inaccommodating a state of unbalance wherein counterbalance forces must beapplied to more than one point of the cylinder.

Fig. 8 is a schematic representation of the cylinder illustrating thesite of overweight to be such as to produce the conditions of Fig. '7.

Fig. 9 is a modified embodiment of the electrical circuit disclosed inFig. 4.

Fig. 10 is a schematic circuit diagram which may be utilized inimproving the precision of the counterbalanc applications.

Fig. 11 is a view similar to Fig. 2 and illustrating further details ofthe weight receiving pockets schematically shown in Fig. 1.

The apparatus comprises an outer shell I 5 supported by base 16 andhaving the usual valved water inlet l1 and the valved waten outlet ordump l8. Within central openings formed in the end walls of shellli aredisposed anti-friction 3 bearings l9 and 20 respectively supportingtrunnions 2| and 22 of the washing cylinder 23.

Washing cylinder 23, apart from the peripheral pockets hereinafterdisclosed, is of generally conventional form and is adapted to containarticles to be washed and damp-dried through the centrifugal extractionof water. Suitable doors 24 and 25, respectively formed in the shell isand washing cylinder 23 are arranged to register with each other so asto permit the introduction or withdrawal of articles from the washingcylinder 23.

Rotating motion is imparted to cylinder 23 .by the variable speedelectric motor 26, the pulley 21 of which drives a belt 23 so as toactuate the pulley 23 connected to the trunnion 22. As is conventionalin apparatus of this type, the slower speeds of motor 26 serve to rotatethe cylinder 23 at a slow or washing speed so that the articles aretumbled about the cylinder and become washed. The cylinder is providedwith the usual ribs, not shown, for agitation or tumbling of theclothes. I

After washing and one or more stages of rinsing, the rotating speed ofcylinder 23 is increased, the dump I3 is opened and the centrifugalforce resulting from the increased speed ejects the water from thewashed clothes whereupon the water flows through the open dump i3 bymeans of the cylinder perforations 30.

After the clothes have been washed at the slow washing speed and therotation of the cylinder has been increased for water extractingpurposes, any unbalanced distribution of the articles in the cylinderwill be manifested by vibration of the cylinder and shell. Suchvibration is a source of noise, wear and danger. It is desirable,therefore, to correct the weight distribution so asto eliminate orneutralize the vibration. Accordingly, means are provided to injectcompensation weight at selected portions of the cylinder 23 so as toequalize the distribution of weight therein. Such weight compensatingmeans takes the form of water pockets 3|, 32 and 33 equally spaced 120degrees apart on the peripheral surface of the cylinder 23. It will beappreciated, however, that the number of water pockets may be varied asdesired and will be spaced accordingly. Furthermore, the pockets may beformed within the conventional agitating ribs, not shown, such as thehollow hydraulic cylinder pockets shown in the application of Leo M.Kahn, Serial No. 610,035, now Patent #2528594, filed August 10, 1945.

The water pockets shown may be secured to the cylinder 23 by means ofrivets, welding or any other suitable means of connection.

Means are provided to inject balancing weight material into the pocketsselectively so as to differenti ally affect the balance of the cylinder.It will be apparent that such material injected into any one of thepockets will modify the peripheral weight distribution and apply acentrifugal force at the site of said one pocket. Trunnion 2| is formedwith three concentrically arranged channels for applying water fromwater pipe 35 to selected pockets of the cylinder. Inner channel 38 isformed with a branch 31, and a continuation pipe 33 which connects withpocket 32 so as to introduce water thereto under specific conditions tobe hereinafter described. Intermediate channel 39 is formed with abranch 40 and a continuation pipe 4| which connects with pocket 33 so asto similarly supply counterbalance fluid thereto. Outer channel 42 isformed with a branch 43 and a continuation pipe 44 which supplies thecounterbalance fiuid to pocket 3|. The

' cylinder.

of the arcuate nature of the pockets as disclosed. I

The floors of the pockets which are comprised of the periphery of thecylinder may be concentric with the longitudinal axis of the cylinderbut, in order to decrease the discharge time, the floors 32a may besloping as shown in Fig. 11 and in the above mentioned prior patentapplication. It will be evident that when the cylinder stops rotating,centrifugal force will no longer maintain the injected water against theceiling of the pockets but, on the contrary, it will flow down andthrough the discharge outlets 34.

counterbalance fluid in the form of water is arranged, through anysuitable source of water under pressure, to flow through pipe 35 intoone or two of the valve openings 48, 49 and 50 respectively connected tothe inner channel-36, the I intermediate channel 33 and the outerchannel- 1 The face 5| of trunnion 2| is formed with 42. threeconcentric troughs 52, 33 and 54 connected respectively with the valveopenings 53, 49 and 43. The purpose of the concentric troughs is topermit water to flow from pipe 35, into a valve opening and thereafterinto one of the water channels notwithstanding continued rotation of theIt will be understood that notwithstanding the radial posltion of thechannels in respect to its complementary valve opening, water maynevertheless flow in any selected trough from the valve openingwhereupon the water will flow into the channel which is connected to theselected trough. In this manner, the water receiving pockets will fillfaster than would be the case were the channels to receive water fromthe valve openings only during such part of the rotation cycle when theselected channel was in alignment with the open valve.

Means are provided to select the course of site of the compensatingfluid by selectively actuating the valves 56, 51 or 58 or any two of thevalves according to the conditions to be corrected. Valves 56, 51 and 58may comprise the armatures of solenoids 59, 60 and Si. It will beunderstood, therefore, that whichever of the solenoids are energizedwill determine the flow of the comcnsating fluid to the particularportions of the cylinder so as to modify the weight distribution thereofas required. The means for the selective actuation of the solenoids areprovided in the electrical circuit hereinaft;r set forth.

The present apparatus applies compensating fluid to selected and spacedpockets during the rotation of the cylinder and in response to aspecific condition of unbalance. It is necessary, therefore, thatinformation be supplied not only concerning the presence of apredetermined degree of unbalance, but the portion of the cylinder wheresuch unbalance exists so that corrective measures may be taken. Suchcorrective measures are, according to the instant invention,automatically put into effect when conditions so require. Meanssynchronized with tharotation of the cylinder are utilized to provide areference voltage by which the instantaneous position of particularportions of the cylinder may be identified or momentarily isolated. Thusthe site of any unbalance can be located, the presence and degree ofwhich is indicated by a vibration responsive device as hereinafterdescribed. We have devised an electrical circuit which reacts to Jointstimuli one of which is a reference voltage and instantaneouslyidentifies or isolates the successive portions of the rotating cylinderwhile the other provides an indication of the degree of unbalance.Jointly, they produce a reaction in the circuit which is so timed by,the reference voltage that the site of the correction is establishedthereby. Such reaction is arrangedto energize one or more of thesolenoids so as to open selected valves and introduce counterbalancefluid into selected peripheral portions of the cylinder during itsrotation.

In order to determine the degree of unbalance, a magnetic, vibrationpick-up device may be utilized. It is apparent, however, that anyequivalent device such as a strain gauge pick-up may be used. It will.be understood that the pick-up not only determines the degree ofunbalance but correlates such information with the site of the unbalancedepending upon the phase of the electrical signal produced by thepick-up. The output of the pick-up, as is well understood, is ofsubstantially sine wave form produced pursuant to the vibrations of thecylinder in a condition of unbalance. A magnet 65, connected by bracket66 to an external support is arranged to co-act with pick-up coil 68 soas to cause the induction of alternating voltages therein. An arm 69having a contact is spring pressed against the shaft 61 and connected soas to shift the coil 68 and cut the magnetic field in accordance withthe vibration of the shaft. It will be recognized by those skilled inthe art that the representation of the pick-up device in Fig. l isschematic and that any conventional apparatus such as a piezo-electriccrystal pick-up may be employed.

The sine wave voltages as applied to the electrical lead wires II and 12are fed to an amplifier .13 for the usual amplification purposes. Sincethe sine wave voltages may be of a low frequency, amplifier 13 may be ofthe direct coupled type or any amplifier adapted to accommodate currentsof low frequency. These sine wave voltages are thereafter fed to aselector H, which, as hereinafter described, is an electrical networkhaving electronic tubes for selecting the valves to be actuatedaccording to the information supplied to it in the form of electricalsignals or intelligence. It is desirable to avoid actuation of thesystem by harmonics of the sine wave voltages if any are present. Thismay be accomplished, as will be recognized by those skilled in the art,by providing suitable filters in the input of amplifier 13. Since theunbalance correction need not be instituted until high speed rotation ofthe cylinder, the range of frequencies involved will not be very greatand the filtering thereof may be easily effected.

Means are also provided to isolate or identify spaced peripheralportions of the rotating cylinder so as to correlate the informationsupplied thereby with that supplied by the vibration pickup.

Referring to Fig. 4, a distributor disc 15 is mounted on the shaft 61 soas to rotate together with the cylinder 23. The distributor is arrangedto successively apply electrical voltages to the brushes 16, I1 and 18.In the embodiment of Fig. 4, the power supply 18 may comprise a di rectcurrent source in the order of 150 volts to which is connected the wiperarm 88. Arm 80 makes wiping contact with ring 8| which is ofelectrically conducting material. Integral with ring 8| is a voltagetransmitting contact segment 82 which preferably, but not necessarily,occupies approximately degrees of the ring 8| for purposes to behereinafter described. Asthe distributor disc 15 rotates together withthe cylinder 23, the volts potential from power supply 18 issuccessively applied to each of the bligfihes as the segment 82 makescontact therew Energizing means for each of the solenoid coils 58, 66and 6| are provided in the form of electronic tubes 62, 63 and 64 ofwhich the respective solenoid coils constitute the plate loads thereof.Tubes 62, 63 and 64 are preferably, but not necessarily, of theThyratron type which are capable of handling large amounts of power. Itwill be apparent that voltages for the plates 65, 66 and 67 of each tubeare applied respectively and successively by means of the brushes TI, 18and I6. Suitable bias for the tubes may be employed and the gridsthereof may be grounded through the usual high grid leak resistance, ifdesired. Two or more Thyratrons, or any number of gas-filled tubes, maybe used in parallel for each solenoid, if necessary.

As the distributor disc 15 rotates, each tube will successively haveplate voltage applied thereto at the same time that the amplified sinewave voltage from the vibration pick-up is applied to the grids thereof.This will set up a condition where the current flow in the plate circuitwill be governed by the phase relationship of the grid and platevoltages. In one sense, it may be considered that the voltages appliedto each plate are alternating. Since the phase of the grid voltage willdepend upon the site of unbalance, variations ofsuch site will vary therelative phase of the two voltages on each tube, that is, the relativetime at which they reach their peak values. If the phase of the gridvoltage lags the plate voltage by degrees, the plate current will beentirely out off. When both the grid and plate of any tube is positive,plate current'will flow, the positive value of grid current dependingupon the firing voltage in the tube as determined by its constants andthe bias thereon. If in a modified circuit valve actuation is dependentupon negative grid voltage, the same principles will obtain as where thede-energization of a tube releases a relay or the like which closes thecurrent to valve actuating means.

Referring to Fig. 5, the X marks a point in the loaded cylinder whereinan overweight exists. In order to establish balance, it is necessary toapply the material to pocket 32. Assuming, therefore, that thedistributor disc 15 is so keyed to shaft 6'| so that positive voltagesare successively applied to the circuits controlling the ap plication ofcounterbalance fluid to pockets 3|, 32 and 33 in that order, each suchcircuit will be successively primed so as to conduct whenthe gridvoltage reaches its positive firing value. Referring to Fig. 6, thesquare wave 85 may represent the plate voltage on tube 64 the solenoidwinding 6| of which controls the armature valve 58 which in turncontrols the application of counterbalance fluid to the pocket 8|. Afterthe distributor has moved approximately 110 degrees, the plate voltageto tube 64 will be cut off and approximately 20 degrees thereafter willbe applied as square wave 86 to the plate 86 of tube 83 which controlsthe application of counterbalance fluid to pocket 92. Similarly. squarewave I1 is shortly thereafter applied to the plate 65 of tube 62, thevoltage 66 having previously been removed from the plate 66. The cyclethereupon repeats itself as illustrated in Fig. 6. At the same time thatthe plate voltages are successively applied to the three tubes, the sinewave pick-up voltage generated by the vibration of the cylinder isapplied to the grids ll, 69 and 90 of the respective tubes. The pick-upapparatus is so disposed on the shaft 61 in relation to the distributorconnection thereto, that the grid voltage 9| generated pursuant to theunbalance at point X in Fig. 5, produces a trough at approximately thesame time that voltage 66 is applied to plate 61. The crest of the gridvoltage 9| appears during the period when voltage 66 is applied to tube66. When voltage 61 is applied to the plate, voltage II is once moredescending into its trough. The ilring voltage 92 is that potential atwhich the grid must be in order to fire the tube at its conditions ofoperation. The values are well known .to those skilled in the art andare determined as hereinabove set forth. Assuming that the firing gridvoltage in a particular design of circuit is 10 volts of positivecurrent, the tube 63 will fire when the grid voltage reaches the dottedline 92 representing the firing voltage. Considerable plate current willflow through the tube 69 so as to actuate the valve 61 and permit fluidfrom pipe II to be applied to the pocket 31. The fiuid will therefore becorrectly applied so that the cylinder approaches a condition ofbalance. It may be desirable if large degrees of unbalance are to beexpected. to limit the amplitude of the grid voltage so that the widthof its positive portion is not appreciably greater than that of thesquare wave plate voltage. As will be apparent to those skilled in theart, this may be done by a delayed automatic volume control (AVC)circuit in the amplifier, or by mechanical limiting means against theshaft 61.

The broken lines defining the grid voltage peak in Fig. 6 illustrate thesimultaneous application of the vibration signal and plate voltage totube 63. It will be understood that as the counterbalance fluid isunblocked from pocket 32 by the actuation of valve 51, the amplitude ofthe grid voltage will decrease as the vibration decreases pursuant tothe correction of unbalance.

when the amplitude is such as to descend below the firing voltage 92,the tube 69 will be extinguished notwithstanding the coincidence of theplate and grid voltages. It is a recognized characteristic of gas-filledtubes of the Thyratron type that mere removal of grid firing voltagedoes not per se produce tube extinction. However, our method of removingthe plate voltage by the distributor means described insures properextinction of the tubes since it is well known that the absence of platepotential will produce this effect. Thus, the present invention anadjacent portion. For this reason, the segso as to decrease thepossibility of consequent erratic operation which might otherwise ensue.

Referring to Fig. 6, if the grid voltage 9| were shifted slightly eitherto the left or right so as to overlap square wave 96 in regard to timeor phase, it would not reach either ofthe adjacent plate voltages so asnot to,be coincident therewith. Accordingly, a margin isprovided whereincorrective action is not tak so that the angular sensitivity isdecreased thereby. when, however, the pocket 32 has been supplied withsumcient counterbalance fluid to represent a force of the necessarymagnitude. the total vibration will be so little that the firing voltageline 92 will not be reached and compensation will cease.

Since the tubes will successively extinguish as the distributor rotates,under ordinary conditions the valves would be de-actuated between firingperiods so that counterbalance iiuid would only flow when the tube wasfiring and the water would therefore flow in spurts. In order toeliminate such periodic action, means are taken to continue theenergization of the solenoids for a period after the tube associatedtherewith has been extinguished and until the tube re-flres when theplate voltage is re-applied thereto.

Accordingly, hold-over circuits in the form of condensers 96, 96 and 91are connected across the respective solenoid windings. The distributoraction will charge'each condenser each time that plate voltage isapplied to the tube associated therewith. when the source of voltage isremoved, the condenser will maintain energization of the solenoid bydischarging therethrough. The value of condensers 96, 96 and 91 will bechosen so as to produce a time constant network which is correlated withthe speed of cylinder rotation. It will be apparent that if the cylinderrotates three times a second, for example, the time constant may be inthe order of one-third of a second and the hold-over circuit elementswill be selected according to well known standards. By this means, whenthe correct pocket or pockets have been selected for the introductionofcounterbalance material, the application of such material will becontinued to such pocket until balance is achieved notwithstanding theperiodic extinction of the tube which controls its valve.

In Fig. 8, the x marks a point in the loaded cylinder wherein anoverweight exists. In order to establish balance in such a condition, itis necessary to apply the counterbalance material simultaneously topockets 3| and 92. Referring to Fig. '7, it will be seen that the phaseof the plate voltages remains fixed, being in the same phase asillustrated in Fig. 6. This, of course, is because the keying of thedistributor disc II to shaft 61 remains undisturbed and at all timesthereafter determines the phase of the plate voltages. The grid voltage99 has, however, shifted approximately 45 degrees as determined by therespective X points in Figs. 5 and 8, so that the positive peak of thegrid voltage is coincident with both plate voltages 66 and 61.Accordingly, both tubes 62 and 64 will fire whereupon the consequentactuation of valves 66 and 66 will effect the introduction ofcounterbalance material to the pockets 3| and 32 simultaneously. It willbe understood, therefore, that more than one, but less than all ofcourse, of the pockets may be filled simultaneously in response to acondition of unbalance.

Whereas a cylinder having three pockets has been shown, it willbeobvious that many. more such pockets may be provided if finer degrees oftacting segment of an extent commensurate with thedivision of thenumber. of pockets into 360 1 degrees as will be evident. Furthermore,other methods of applying the plate voltages may be employed, such asthat of a pilot generator which produces. plate voltages from therotation of the cylinder itself and eliminates the necessity of a powersupply. a

In Fig. 9 is illustrated a modified embodiment of the selector circuitwherein ordinary vacuum tubes may be employed. In this case, the platevoltages are constantly applied to the tubes I00, III and I02. However,the vibration pick-up grid voltages are distributed to the grids I 03,I04 and I05 through the distributor disc I08. The wiper arm I01 isconnected to one terminal of the amplified vibration pick-up voltage,the other terminal of which may be suitably grounded. The contactsegment I08 receives the gridvoltages and applies them through thebrushes I00, H and III to the grids as aforesaid. As before, the phaseof the grid voltage will depend upon the site of unbalance. As thisvoltage is distributed to the grids, it is broken up into threecomponents one or more of which,

but less than all, will include the positive -portion of the gridvoltage. The bias of each tube is arranged as by cathode bias resistorsI I 0,- I I and I I0 so that the tube will conduct at a predeterminedgrid potential. Conventional means are provided to maintain the tubesnormally at or near their cut off state so that thesolenoids II'I, H8and H9 are not energized. However, whichever 0f the tubes receives thepositive portion of the pick-up signal of proper amplitude 'will conductso as to open the correct valves and approach or effect balance ashereinabove described. The usual grid leak resistors I20, I2I and I22are provided and the holdover condensers I23, I 24 and I 25 form a timeconstant network therewith for the purposes above described. SincetubesI00, IN and I02 are riot of the gasfilled type, they may be cut oil!without removing the plate voltage but ordinarily such tubes, unlessmade very large, can not handle adequate power. Accordingly, it may bedesirable to provide a plurality of such tubes in parallel, or thesolenoids III et seq may take the form of relays for closing anotherpower circuit which will suit-. ably actuate the necessary valves.

In Fig. is illustrated an additional safe-, guard for eliminating apossibility of erratic op-" eration or hunting. in the apparatus. Forexample, should a pocket overfill due to lag in operation of anysolenoid, the site of unbalance would be shifted to a diametricallyopposite point and further correction would be made by applying thefluid to diiferent pockets. It is desirable,

however, to provide a margin of tolerance where-* by a slightover-correction will not shift the application of counterbalance fluid.The firing voltage level 92 is ordinarily set by the bias on the gridsB8, 89 and 93 of the valve control tubes. Such bias may be app ied tothe grids t rough a spring arm I30 having a contact point I3I whichnormally makes electrical contact with terminali32 which is connected toa negative point of voltage I33. However, when any one of the valves 50.51 or 58 is actuated, it li ts arm I30 so thatcontact I3I removes thebias of point I33 and contact I34 is caused to meet arm I35 which isconnectedto a less negative voltage point I30. Correction will thereuponcontinue until the pick-up'voltage 'is so low that it does not reach thefiring'voltage line represented by the lower firing voltage point I36.After correction has been established and the actuated valve hasreturned to normal position, the arm I30 will likewise be restored tonormal position and the higher bias will then be applied so that aslight overflow will not produce .sufiicient amplitude of firing voltageto strike at the new point of operation. This feature will be furtheruseful in avoiding erratic operation as the water is extracted from theclothes during the extracting process so as to change the weightdistribution. However, since the great bulk of the water is extractedduring the'beginning of the extracting operation "and since properbalancing has been initially approached, subsequent unbalance will be ofconsiderable less importance.

We have shown a preferred embodiment of our invention, but it is obviousthat numerous changes and omissions may be made therefrom withoutdeparting from its spirit. For example, while we have illustrated theachievement of balance through theaddition oi counterbalance fiuid toselected sites on the periphery of the cylinder, it will be apparentthat the invention can be adapted toward the release of fluid from anormally filled pocket. In other words, the vibration responsive devicewould be so situated with respect to the distributor contact segmentthat a valve of a receiving element at the site of unbalance would beactuated so as to. release water from the pocket at that site. Obviouslya source of water supply from the pipe will not be required in such anembodiment and the release of water will serve tomodify the peripheralweight distribution of the cylinder. Furthermore, since the invention isadapted toward the release of fluid from anormally filled pocket, it ispossible to provide balancing apparatus in a two pocket cylinder. Insuch a structure it would be unnecessary to provide the water-tightbearing means illustrated in Figs. 2 and 3 hereof since thecounterbalance fluid may be removed or applied centrally of thetrunnions. A structure illustrating a cylinder with two cally opposed"water receiving pockets and providing for the application of fluidthereto through the cylinder trunnions is illustrated in the abovementioned sole patent application of Leo M. Kahn Serial No. 620,038.However, in an embodiment con tructed according to the instantinvention, the two pockets would be spaced degrees apart on the cyl nderand the balance may be achieved by providing means for both adding waterand releasing water selectively from either pocket. It will berecognized that the provision for either removing or releasing waterfrom a pocket wherein two pockets spaced at 90 degrees are provided, isequivalent to providing four pockets spaced at 90 degrees whereincounterbalance fluid can be either removed or applied, but not both. Asregards the use of a pi ot generator mentioned above, it will berecognized by those skilled in the art that the generator would producea reference sine wave voltage instead of the square waves produced bythe distributor. reference sine wave would be correlated witlf't time.By applying the phases of the pilot gen.-

diametri- Ho ever, the" phase of the asaaaes therewith may selectivelyclose electrical cir-.

cuits tor actuating the proper valves.

As will be apparent to those skilled in the art, the amplifier II willbe capable of gain adjustment so that the unbalance indications can beamplified as desired. Similarly, the bias on the tubes may be adjusteddepending upon the level at which correction is desired.

We claim:

l. Balancing apparatus for a rotating cylinder for housing wet articlesfrom which liquid is to be centriiugally extracted, comprising a seriesof counterweight receiving elements loca at spaced peripheral portionsof said cylinder, means to feed liquid counterweight material to saidreceiving elements, inlet controls for blocking said material from saidreceiving elements, control operating means for selectively unblockingat least one or said receiving elements so as to introduce saidcounterweight material thereto, a vibration responsive device forproducing a series of electrical response pursuant to vibrations of saidrotating cylinder, means synchronized with its. rotation forsuccessively establishing the instantaneous angular position oi saidspaced portions of said cylinder, and means jointly controlled by saidseries of electrical responses and by said synchronized means foractuating said control operating means.

2. Balancing apparatus for a rotating cylinder for housing wet articlesfrom which liquid is to be centriiugally extracted, comprising a seriesoi counterweight receiving elements located at spaced peripheralportions of said cylinder, means to feed counterweight material to saidreceiving elements, inlet controls for blocking said material from saidreceiving elements, inlet control operating means for selectivelyunblocking at least one oi! said receiving elements so as to introducesaid counterweight material thereto, a vibration responsive device forproducing an electrical voltage of substantially sine wave form pursuantto vibrations of said rotating cylinder, means synchronized with itsrotation for successively establishing the instantaneous angularposition of said spaced portions of said cylinder, and means jointlycontrolled by the amplitude oi. a predetermined portion of said sinewave voltage and by said synchronized means for actuating saidunblocking means.

3. Balancing apparatus for a rotating cylinder comprising a plurality ofweight receiving elements adapted to receive weight counterbalancematerial from a source thereof, control means for selectively applyingsaid material to control said receiving elements, said weight receivingelements being respectively disposed in spaced portions of said cylinderso as to difierentially ailect the balance thereof when saidcounterbalance material is selectively applied thereto, a vibrationresponsive device adapted to produce a first electrical output pursuantto the vibration of the rotating cylinder, said control means comprisingnormally inactive electronic tubes associated with each of saidreceiving elements, plate and grid electrodes in said trically establishthe angular positions of said weight receiving elements of said rotatingY inder so as to produce a series oi second electrical outputs eachcorrelated with a Sp i weight receiving element or said cylinder andmeans to apply both a predetermined controlling portion of said firstelectrical output and one of said series of second electrical outputs toat least one or said electronic tubes in said control means so as toactuate said one electronic tube when a predetermined degree ofvibration exists in said rotating cylinder whereby counterbalancematerial is applied to the receiving element associated with said oneelectronic tube, ot r portions oi. said first electrical output be gapplied to other tubes so as to continue said other tubes in theirnormally inactive state.

4. Balancing apparatus according to claim 8 including valves controlledby said control means for introducing counterbalance material to saidreceiving elements, and solenoids in the plate circuits or saidelectronic tubes, said solenoids.

being operative to actuate said valves whereby said material may fiowinto said receiving elements when the electronic tube associatedtherewith is actuated so as to energize the solenoid in its platecircuit.

5. Balancing apparatus according to claim 3 including valves controlledby said control means for introducing said counterbalance material tosaid receiving elements, solenoids in the plate circuits of saidelectronic tubes, said solenoids being operative to actuate said valveswhereby said material may fiow into said receiving elements when theelectronic tube associated therewith is actuated so as to energize thesolenoid in its plate circuit and a hold-over device in the platecircuit oi. each electronic tube so as to .maintain energization or itssolenoid alter the electronic tube associated therewith is de-actuated.

6. Means for balancing vibration in a rotating cylinder comprising aplurality of weight receiving elements adapted to selectively receivecounterbalance weight material, from a source thereof, control means forselectively applying said material to said receiving elements, avibration responsive device adapted to produce an electrical outputpursuant to vibration oi the rotating cylinder, said plurality 01'weight receiving elements being respectively disposed in spacedperipheral portions oi said cylinder so as to difierentially afiect thebalance thereof when counterbalance material is selectively appliedthere! to. valves included in said control means for controlling theapplication 01' said material to said receiving elements, an electronictube circuit for each of said valves, each said electronic tube circuitbeing associated with one of said receiving elements, each tube in saidcircuits having at least plate, grid, and cathode electrodes, a sourceor plate potential, distributor means synchronized with the rotation ofsaid cylinder for successively applying said potential to the plates ofsaid tubes, means for simultaneously applying the output 01' saidvibration responsive device to the grids oi said tubes, said tubes beingresponsive to a predetermined coincidence oi voltage conditions on theirrespective plates and grids for actuating said valves so as to applysaid material. selectively to said receiving elements.

7. Balancing apparatus according to claim 8 wherein said vibrationresponsiv device electrielectronic tubes, means to successively eleccaloutput is a sine wave, and said coincidence or voltage conditionscomprises .the simultaneout application or a positive portion or saidsine wave of predetermined amplitude on any grid oi said tubes andapplication oi plate potential to said tube whereby the selectedactuation 01 valves in said control means depends upon the phaserelationship of the grid and plate voltages.

6. Balancing apparatus according to claim 6 wherein said vibrationresponsive device electrical output is a sine wave, and said coincidenceof voltage conditions comprises the application oi a positive portion orsaid sine wave and of a predetermined amplitude thereof on the grid of'any or said tubes, and th simultaneous application of plate voltage tothe plate of said tube, whereby the selected actuation of valves in saidcontrol means depends'upon the phase relationship of the grid and platevoltages, the application of voltages to the plates being synchronizedwith the rotation of said cylinder so as to have a relatively constantphase, said grid voltage having a varying phase depending upon the siteof unbalance, the frequency of the grid voltage being lower than that ofthe plate voltage in proportion to the number of receiving elements inthe apparatus, saidnumber being at least three so that said conditionsof coincidence may occur in more than one tube whereby more than onereceiving element may be supplied with said counterbalance weightmaterialat any one time.

9. Balancing apparatus according to claim 6 wherein said tubescomprisegas-filled electronic tubes adapted to fire under predeterminedconditions of grid voltage and wherein said vibration responsive deviceelectrical output is a. sine wave, and said coincidence of voltageconditions comprises the application oi' a positive portion 01' saidsine wave and of a predetermined amplitude thereof on the grid of any ofsaid tubes and the simultaneous application of plate voltage to theplate of said tube, whereby the selected actuation of valves in saidcontrol means depends upon the Phase relationship of the grid and platevoltages, the application of voltages to the plates being synchronized.with the rotation of said cylinder so as to hav a relatively constantphase, said' grid voltage having a varying phase depending upon the siteof unbalance, said phase variation of grid voltage with respect to platevoltage being such that said conditions of coincidence may occur in morethan one tube whereby more than one gas-filled tube may firesimultaneously and more than one receiving element may be supplied withsaid counterbalance weight material at one time.

10. Balancing apparatus according to claim 6 wherein said vibrationresponsive device electrical output is a sine wave, and said coincidenceof voltage conditions comprises the application of a positive portion ofsaid sine wave and of a predetermined amplitude thereof on the grid ofanv of said tubes and the simultaneous application of plate voltage tothe plate of said tube, whereby the selected actuation of valves in saidcontrol stores said coincidence of voltage conditions to said tubebefore said valve is de-actuated.

11. Balancing apparatus according to claim 6 including means to separatethe successiv applications of plate potential to the plates of saidtubes whereby said voltage condition on a grid may overlap the platevoltage in a tube in extent of time without being brought into timecoincidence with the plate voltage or an adjacent tube.

-12. Balancing apparatus according to claim 6 including means toseparate the successive applications of plate potential to the plates ofsaid tubes whereby said voltage condition on a grid may overlap theplate voltage in a tube in extent of time without being brought intotime coincidence with the plate voltage of an adiacent tube. said meansto separate the successive applications comprising a series of radialsegments on said distributor means, each of said segments beingconnected to the respective plates of said tube and having platepotential successively applied thereto so as to successively transfersuch potential to said plates, said segments occupying an arcuate area01' less than a predetermined fraction of 360 degrees, said fractionresulting from a division of 360 degrees of cylinder periphery by thenumber of receiving elements thereon.

13. Means for balancing vibration in a rotating cylinder comprising aplurality of weight receiving elements adapted to selectively receivecounterbalance weight material, from a source thereof, control means forselectively applying said material to said receiving elements, avibration responsive device adapted to produce an electrical output ofsine wave form pursuant to vibration ofthe rotating cylinder, saidplurality of weight receiving elements being respectively disposed inspaced peripheral portions of said cylinder so as to .difierentiallyaffect the balance thereof when counterbalance material is selectivelyapplied thereto, valves included in said control means for controllingthe application of said material to said receiving elements, anelectronic tube circuit for each of said valves, each said electronictube circuit being associated with one of "said receiving elements, eachtube in said circults having at least plate, grid and cathodeelectrodes, a potential supply for the plates of said tubes, distributormeans synchronized with the rotation of said cylinder for successivelyapplying portions oi the sine wave output of said vibration responsivedevice to the grids of the tubes whereby each grid receives an equalportion of said sine wave, the positive portion of said sine wave beinglimited to lessthan all of said grids. said positive portion beingoperative to actuate the tube, the grid of which it is applied towhereby the valve associated with said tube is actuated so as to applysaid material selectively to said receiving elements.

14. Balancing apparatus for a rotating cyl nder comprising a vibrationresponsive device adapted to produce a first electrical output pursuantto vibrations of the rotating cylinder,

means to electrically establish the angular position of spaced portionsof said cylinder during its rotation so as to produce a secondelectrical output thereby, means iointly actuated by a predeterminedlevel of said first electrical output and by said second electricaloutput for applying a counterbalance force to said cylinder asdetermined by both a predetermined extent of unbalance indicated by saidfirst electrical output and the site of said unbalance as determined bysaid second electrical output, and means to increase the actuating levelof said jointly actuated means after a counterbalance force has beenapplied whereby said vibrations must rise to a substantially higheramplitude after such application in order to resume the application ofcounterbalance forces thereby.

15. Balancing apparatus for a rotating cylinder for housing wet articlesfrom which liquid is to be centrifugally extracted, said cylindercomprising a plurality of weight receiving elements arranged to containquantities of counterbalance material, control circuit means forautomatically regulating the quantity of such material in the respectiveelements, said receiving elements being respectively disposed inangularly spaced peripheral portions of said cylinder so as todifferentially affect the balance thereof depending upon the quantitiesof counterbalance material contained in the respective receivinglements, an electrically controlled vibration responsive device adaptedto produce an electrical signal pursuant to the site of overweight ofsaid articles in the rotating cylinder, said control circuit means beingautomatically actuated by said electrical signals so as to vary thecounterbalance material contents of at least one of said receivingelements during a state of unbalance of the rotating cylinder, saidcontrol circuit means being continuously operable during rotation ofsaid cylinder and during gradual liquid extraction of said articles soas to continue the automatic varying of said contents as said site ofoverweight may shift.

16. Balancing apparatus for a rotating cylinder for housing wet articlesfrom which liquid is to be centrifugally extracted, comprising avibration responsive device arranged to produce an indication ofunbalance pursuant to vibrations of the rotating cylinder, inlet controlmeans to supply counterbalance material from a source thereof to spacedperipheral portions of said rotating cylinder, rotating means forsuccessively establishing the angular position of said spaced portionsof the rotating cylinder, inlet control actuating means jointlycontrolled by said vibration responsive device and said rotating meansfor selectively actuating said inlet control means so as to supply saidmaterial to one or more of said spaced portions, and a hold-over memberto continue supplying said material to said one or more of said spacedportions during continued rotation of said cylinder.

17. Balancing apparatus for a rotating cylinder for housing wet articlesfrom which fluid is to be centrifugally extracted, comprising aplurality of weight receiving elements arranged to receive weightcounterbalance material from a source thereof, control means forselectively applying said material to said receiving elements, saidweight receiving elements being respectively disposed in spacedperipheral portions of said cylinder so as to differentially affect thebalance thereof when said counter-balance material is selectivelyapplied thereto, a vibration responsive device arranged to produce afirst electrical output pursuant to the vibration of the rotatincylinder, means to successively electrically estabelements of saidrotating cylinder so as'to produce a cyclical series of secondelectrical outputs corresponding to such angular position, said controlmeans being connected to receive said first and second electricaloutputs and being actuated jointly by a time coincidence of said firstelec-. trical output and less than all of the second electrical outputsof any one cycle so as to app y' said material to at least one of saidreceiv 8 elements selected according to the amplitude of vibrationoccurring during the establishment of the angular position of one ormore receiving elements.

l8. Balancing apparatus according to claim 17, including means tocontinue said application of said material to said selected receivingelements during continued rotation of said cylinder and subsequentestablishment of the angular position of the remaining receivingelements by said series of second electrical outputs.

19. Balancing apparatus according to claim 17 including an electricalhold-over network of a value correlated to the speed of rotation of saidcylinder whereby said Joint actuation of said control means is held overbetween periods when the electrical output establishing the angularposition of selected receiving elements is-applied, coincidental withsaid first electrical output, to said control means.

20. Balancing apparatus for a rotatable hollow cylinder of a machine fortreating discrete articles comprising a plurallty'of weight receivingelements arranged to house varying amounts of weight counterbalancematerial, said weight relish the angular position of the weightreceiving ceiving elements being angularly disposed around said cylinderso as to differentially affect the balance thereof pursuant to thevarying amounts ofsaid material housed therein. inlet control meansincluding an electrical circuit for selectively varying the amounts ofsaid material housed in said receiving elements, a vibration responsivedevice arranged to provide an electrical voltage pursuant to the passageof an overweighted portion of the rotating cylinder, and referencemeanscontinuously operative during the rotation of the cylinder forregistering the momentary angular disposition of each weight receivingelement, said inlet control means being controlled jointly by saidvibration responsive device electrical voltage and the action of saidreference means so as to vary the amounts of said material in one ormore of said weight receiving elements depending upon the site of saidoverweighted portion.

21. Balancing apparatus for a rotatable hollow cylinder comprising aplurality of weight receiving elements arranged to receivecounterbalance liquid from a source thereof, said weight receivingelements being respectively disposed adjacent spaced-periphe'ralportions of said cylinder so as to diflerentially affect the balancethereof when said liquid is selectively applied thereto, inlet controlmeans for selectively applying such liquid to such receiving elements, avibration responsive device arranged to provide an electrical voltage ata time coinciding with the passage of an overweighted portion of therotating cylinder, reference means operative by the rotation of thecylinder for registering the momentary angular disposition of eachweight receiving element, said control means being activated Jointly bysaid vibration responsive device and said reference means so as to applysaid liquid to one or more of said weight receiving elements which arein a portion of said cylinder substantially opposed to said overweightedportion, and a hold-over element acting on said control means wherebysaid control means acts to continue the application of said liquid afterthe joint control thereof terminates.

22. Balancing apparatus for a rotatable hollow cylinder comprising aplurality of weight receiving elements arranged to receivecounterbalance liquid from a source thereof, said weight receivingelements being respectively disposed adlacent spaced peripheral portionsof said cylinder so as to differentially affect the balance thereof whensaid liquid is selectivelyapplied thereto, an inlet and inlet controlmeans for each weight receiving element including an electrical circuitfor selectively applying such liquid to said receiving elements, avibration responsive device arranged to produce an electrical voltagehaving one voltage peak during each revolution of the rotatingunbalanced cylinder and occurring at a time coinciding with the passageof an overweighted portion of the rotating cylinder, reference means forestablishing the identity of any one of said receiving elements as thereceiving element passes a predetermined line during its rotatingtravel, said reference means being operative to produce a series ofvoltage peaks each corresponding to one of said receiving elements, saidreference means voltage peaks successively following each other in timeand having a higher frequency than said vibration voltage whereby thetime duration of said vibration voltage peak may cause it to overlapmore than one reference means voltage peak depending upon their phaserelationship, said inlet control means being operated by a timecoincidence of a vibration voltage peak and a reference means voltagepeak so as to apply said liquid to the receiving element whose referencemeans voltage peak coincides with the vibration voltage peak in any onerotation of the cylinder, whereby the liquid may be simultaneously fedto more than one receiving element.

23. Apparatus according to claim 22, wherein said vibration voltage isof substantially sine wave form and of the same frequency as that of therotating cylinder so that its peak occupies almost one half of therotating cycle, said reference means voltage peaks being at least threein number and being equally spaced through said rotating cycle.

24. Balancing apparatus for a rotatable hollow cylinder comprising aplurality of weight receiving elements arranged to receivecounterbalance liquid from a source thereof, said weight receivingelements being respectively disposed ad- Jacent spaced peripheralportions of said cylinder so as to differentially affect the balancethereof when said liquid is selectively applied thereto, an inlet andinlet control means for each weight receiving element including anelectrical circuit for selectively applying such liquid to saidreceiving elements, a vibration responsive device arranged to provide anelectrical voltage having one voltage peak during each revolution of therotating unbalanced cylinder and occurring at a time coinciding with thepassage of an overweighted portion of the rotating cylinder, referencemeans for establishing the identity of any one of said receivingelements as the receiving element passes a predetermined line during itsrotatin travel, said reference means being operative to produce a seriesof voltage peaks each corresponding to one of said receiving elements,said reference means voltage peaks successively following each other intime and having a higher frequency than said vibration voltage wherebythe time duration of said vibration voltage peak may cause it to overlapmore than one reference means voltage peak depending upon their phaserelationship, said inlet control means being operated by a timecoincidence of a vibration voltage peak and a reference means voltagepeak so as to apply said liquid to the receiving element whose referencemeans voltage peak coincides with the vibration voltage peak in any onerotation of the cylinder, whereby the liquid may be simultaneously fedto more than one receiving element, and a holdover circuit in theelectrical circuit of each valve control means, said hold-over circuitbeing a time constant network having a time delay approximating the timeof one rotation of the cylinder.

LEO M. KAHN. EDWIN ELLNER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,554,014 Mac Farland sept. 15,1925 1,604,748 Grauer Oct. 26, 1926 2,235,393 Baker Mar. 18, 19412,322,561 Bevins et a1. June 22, 1943 2,331,733 Senger Oct. 12, 19432,346,975 Laboulais Apr. 18, 1944 FOREIGN PATENTS Number Country Date399,845 Great Britain Oct. 13, 1933

